The 2008 White House race turned dirty yesterday when a report charged that Sen. Barack Obama had been raised as a Muslim and that he concealed it – claims the Democrat’s campaign promptly slammed as a smear.

The story on the Web site of the conservative magazine Insight alleged that Democrats “connected” to Hillary Rodham Clinton had discovered that Obama had studied at a madrassa – a Muslim religious school – for four years while living in Indonesia with his mom.

The story, citing anonymous sources, claimed that opposition research “within the Democratic Party” turned up the information, and that Obama had omitted the details from his two top-selling memoirs, “Dreams of My Father” and “The Audacity of Hope.”

Instead, the article claimed, Obama only “alluded” to attending a mostly Muslim school.

The claims were clearly aimed at both punching holes in Obama’s biggest asset – his authenticity – while trying to instill fears among voters who connect Islam to terrorism. It also painted the Clinton camp as being behind the slime job.

Obama’s top strategist, David Axelrod, strongly denounced the story as a fabrication.

“This is the kind of divisive, destructive garbage that has littered our politics for a long time,” Axelrod said.

“He was not raised as a Muslim, and he did not go to a madrassa. It is a complete contrivance, and its purpose is clear. They’re just selling people short.”

In his book and in interviews, Obama has talked about his father, a non-practicing Muslim who divorced his mom when he was 2 years old and moved back to Kenya.

His mother remarried and moved to Indonesia, where Obama studied for two years at a private school and then two years at a Catholic school – all before his teenage years. Axelrod said the private school was not religious.

He said it was attended predominantly by Muslim kids, and there was a weekly comparative religion course.

Obama and his family currently attend the Trinity United Church of Christ in Chicago.

The Insight piece claimed the “research” about Obama was done by people “connected” to Clinton’s camp, but Axelrod said he didn’t “believe that for a second.”

Clinton’s aides blasted the story as an attempt to tar both her and Obama. “We have no connection to this story,” said spokesman Howard Wolfson, noting the magazine is owned by the Rev. Sun Myung Moon-founded Unification Church.

“It is an obvious right-wing hit job by a Moonie publication and an attack on both Sen. Clinton and Sen. Obama.”